Portable derrick



NOV. 23, 1954 D, I S 2,695,082

PORTABLE DERRICK Filed Jan. 29, 1951 2 Sheets-Sheet l 9 1/ F FL i=5 j? SEE: 2': J6 3 -37 F|G.4. 9 C-: 1 1 71: 14

30 3; FIG. 9 if M INVENTOR. IO. EDGAR D. MILLS BYWW ATTORNEY Nov. 23, 1954 E, D.' MILLS PORTABLE DERRICK 2 Sheets-Sheet 2 5 INVENTOR.

Filed Jan. 29, 1951 y EDGAR D. MILLS ATTORNEY United States Patent PORTABLE DERRICK Edgar D. Mills, Mattoon, Ill., assignor to McCabe-Powers Auto Body Co., St. Louis, Mo., a corporation of Missouri Application January 29, 1951, Serial No. 208,265 Claims. Cl. 189-11 This invention relates in general to certain new and useful improvements in portable derricks and, more particularly, to a telescopic single-leg derrick for use on repair trucks and similar mobile platforms.

There are a number of commercial operations, such as public utility repair work, which require frequent use of portable derricks capable of being set up in the vicinity of the work for use in erecting poles, vertical pipes and similar structural elements. At the present time this need or requirement is met by equipping public utility trucks and similar repair vehicles with a plurality of poles, rods, beam-like structures or similar devices which can be assembled in the field into a threelegged derrick or supporting structure. Obviously, the weight and size of these components are substantial and the labor involved in setting them up is appreciable. In fact, a great deal of time and effort are consumed in the erection and taking down of such equipment and frequently the job to be performed with the derrick takes much less time than will be involved in the handling of the derrick itself. Furthermore, the derrickforming component must be relatively long in order to have any satisfactory degree of utility and it is, therefore, necessary to employ long truck bodies for jobs which would otherwise not require such expense for equipment.

It is, therefore, the primary object of the present invention to provide a portable derrick which is simple to transport in a highly compact, lightweight, assembly and can be conveniently set up into operative position upon arrival at the place of use.

It is a further object of the present invention to provide a single-legged derrick-forming device which can be economically constructed and can be readily mounted in the body of a small size truck for compact transportation from place to place and can be set up for actual use with a minimum of labor and lost time.

It is another object of the present invention to provide a single-legged telescopic derrick which can be shifted from fully collapsed to fully opened or operative position through the efforts of a single worker and when in open or operative position will be extremely strong and rigid.

With the above and other objects in view, my invention resides in the novel features of form, construc tion, arrangement, and combination of parts presently described and pointed out in the claims.

In the accompanying drawings (two sheets):

Figure l is a side elevational view of a truck, partly broken away and in section, showing the truck equipped with a single-legged telescopic derrick constructed in accordance with an embodying the present invention;

Figures 2, 3, and 4 are fragmentary sectional views taken along lines 22, 33, and 4-4, respectively, of Figure 1;

Figures 5, 6, and 7 are fragmentary sectional views taken along lines 5-5, 6-6, and 7-7, respectively, of Figure 2; I

Figure 8 is a fragmentary sectional view taken along line 8-45 of Figure 5;

Figure 9 is a fragmentary sectional view taken along line 9-9 of Figure 4;

Figure 10 is a fragmentary perspective view showing the details of construction of a preferred form of locking pin mechanism; and

Figure 11 is a fragmentary perspective view showing the details of construction of a modified form of locking pin mechanism.

Referring now in more detail and by reference characters to the drawings, which illustrate practical embodiments of the present invention, A designates a conventional truck having a rear-mounted utility body B conventionally including side walls 1, a front wall 2, and a floor or bottom wall 3. Bolted or otherwise rigidly fastened to the bottom wall 3, by means of relatively heavy bolts 4, is a base plate b. Welded or otherwise rigidly secured to the upper face of the plate b is an upwardly presented U-shaped channel member 5 and similarly welded at their lower ends to the lateral flanges 6, 6', thereof are spaced vertical side plates 8, 8, the latter being provided upon its inner face with a stop-block 9. Also welded to the lateral flanges 6, 6', of the channel 5 and to the plates 8, 8, respectively, are angularly disposed side plates 14), 10'. At its upper end the web section is cut away so as to provide a U-shaped open space 11 between the upwardly projecting portions of the side plates 8, 8, all as best seen in Figure 2 and for purposes presently more fully appearing.

Journaled at its ends in and extending horizontally between the upper ends of the side plates 8, 8, is a heavy pivot pin 12 to which is rigidly welded a depending U-shaped strap member 13 somewhat narrower than the distance between the inner faces of the plates 8, 8', and being spaced therefrom by spacing collars 14, 14', respectively. Suspended within the bight of, and welded to, the strap member 13 is a short section of tubular steel pipe in the provision of a swingable sheath 15. It will be apparent by reference to Figures 1 and 2 that the sheath 15 extends outwardly on both sides through the strap member 13, so that when in upright position it will extend upwardly for a short distance above the upper end of the uppermost extremity of the plate 8' and will project downwardly for a substantial portion of its length terminating between the plate 10, 10.

At its lower end the sheath 15 is provided with a pair of diametrally aligned apertures 16, 16, positioned for optional registration with pairs of suitably aligned apertures 17, 18, formed respectively in the lateral flanges 6, 6, of the channel 5. Tack-welded upon the outer faces of the lateral flanges 6, 6, of the channel 5 in concentric relation to the apertures 17, 18, respectively, are collars 19, provided with a bayonet slot 20 for receiving a radial pin 21 set into and projecting from a locking pin 22 having a diametral handle bar 23, one end of which is preferably, though not necessarily, provided with a free-swinging securement ring 24 which is connected by means of a section of flexible chain 25 to the plate 10, so that the locking pin 22 will not become lost upon removal. It will also be noted that by aligning the apertures 16, 16, of the sheath 15 with either the pair of apertures 17 or the pair of apertures 18, and correspondingly inserting the locking pin 22, it is possible to set the sheath 15 in one or the otherof the two positions shown in Figure 5.

Upwardly from its lower extremity the sheath 15 is provided with a pair of diametrically opposed apertures 26 arranged along an axis at to the axis of the apertures 16, 16', for receiving a second locking pin 27 also secured against accidental loss by a loose length of chain 28. Slidably or telescopically disposed within the sheath 15 is a long boom-forming section of tubular steel pipe 29 which is, in turn, telescopically provided with a second length of boom-forming tubular steel pipe 30. It will, of course, be understood that the outside diametral size of the section 29 is substantially equal to the inside diametral size of the sheath 15 and similarly the inside diametral size of the section 29 is substantially equal to the outside diametral size of the section 30, so that the several sections slide snugly but nevertheless freely within each other. At their ends the sections 29, 30, are provided with apertures 26, 29, 311', respectively. The apertures 26' align with the apertures 26 for receiving the locking pin 27 and the apertures 29', 3t), align with each other for receiving a locking pin 27 secured against accidental loss by a section of flexible chain 28', as best seen in Figures 7 and 8.

The section 311 is finally provided at its outer ends with a rigidly secured end fitting 31 which is flanged outwardly at an angle and provided with a relatively large aperture .32 into which a pulley or other tool-attachment (not shown) may be fitted or mounted. Just below the fitting 31 the section 36 is provided with a circular loop or eye 33 for receiving a guy-rope 34, all as best seen in Figure 1.

Provided for rigid securement by screws, bolts, or any other conventional means to the front wall 2 of the truck body is a socket element 35 comprising a rectangular socket-plate 36 and an outwardly opening tubular socketforming sleeve 37 preferably formed of a short length of pipe having substantially the same inside and outside diametral sizes as the sheath 15. The sleeve 37 is provided with a pair of vertically aligned diametrally opposed apertures 35 adapted for registration with the apertures 26' in the lower end of the boom-forming member 29, and the apertures 30 in the lower end of the boom-forming member 36. Thus, a locking pin 39 can be dropped through the several sets of aligned apertures just named for retaining both boom-forming members 29, 30, securely within the socket-forming section 37 when the device is in collapsed position, as shown in dotted line in Figure 1.

The side flange 8 is integrally provided adjacent its upper extremity with a laterally projecting ear 4%) provided with an inwardly projecting large-headed bearing stud 41 upon which is rockably mounted a semicircular end fitting 42 which engages the bight portion of an elongated U-bolt 43 having spaced parallel legs 44, 44' which are threaded for a substantial distance along the upper portion of their lengths and at their lower extremities are diametrally reduced and smooth surfaced for loose fitting slidable disposition through a guide block 45 rigidly mounted upon the outer face of the sheath adjacent its lower end.

Disposed encirclingly around the U-bolt leg members 44, 44, are substantially heavy counterbalancing springs 46, 46, abutting at their lower ends against the upwardly presented face of the guide block 45 and at their upper ends against washers 47, 47, which, in turn, bear against the under sides of adjustment nuts 48, 48', respectively, which are, in turn, operatively mounted upon the threaded portions of the leg members 44, 44. As will be seen by reference to Figure 2 the U-bolt 43 and the counterbalancing springs 46, 45, associated therewith work entirely within the narrow space between the sheath 15 and the inner face of the side flange 8 by appropriate adjustment of the nuts 43, 48. The amount of counterbalancing tension imposed. upon the springs 46, 46, may be suitably varied within reasonable limits so that the weight of the boomforming members 29, 30, will be precisely counterbalanced for smooth swinging operation from horizontal or telescoped position into upwardly swung or operative position or the reverse.

In use the locking pin 39 may be removed and the boomforming elements pulled out horizontally through the base section of pipe 16 until they are in fully extended position. The locking pin 27 may be dropped into place securely fastening the boom-forming member 29 within the section of pipe 16 and similarly the locking pin 27' may be dropped into place securely fastening the boom-forming member within the outer end of the boom-forming member 29. Thereupon the boom-forming members 29, 39, may be manually pushed upwardly to the position shown in full lines in Figure 1 and the locking pin 22 inserted therethrough so that the structure will be held in fully upright position. If desired, the guy-rope 34 may then be pulled back and tied around the socket-forming sleeve 37 or any other available fastening element to act as a further stabilizing element for the structure. It has been found in actual practice that the guy-rope may also be used to pull the extended boom-forming members 29, 30. into upright position. The guy-rope 34 is particularly useful for this purpose Where it is necessary to raise the boom-forming members 29, 30, from the interior of the truck body rather than from the ground to the rear of the truck. It will. of course, be understood that the guy-rope 34 is more of a convenience than a necessity since the fully extended structure, when locked together by the locking pins 22. 27, 27, forms an extremely strong rigid and eflicient single-leg derrick.

If desired. it is possible to provide a modified form of locking pin 22. as shown in Figure 11, which includes a radially extending handle 49 welded or otherwise suitably secured in place and provided at its outer end with a flattened portion 50 for locked engagement behind a hook-like catch element 51 fixed in the outer face of the flange 6.

It should be understood that changes and modifications in the form, construction, arrangement, and combination of the several parts of the truck derricks may be made and substituted for those herein shown and described without departing from the nature and principle of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. For use with a vehicular body having a floor and front end-wall, a portable derrick comprising a base element adapted to be securely mounted upon the vehicle floor, an upright member carried by the base, an openended tubular sheath, a fitting rigidly aflixed externally upon the sheath and projecting radially outwardly therefrom, a pivot member mounted in the upright member and extending operatively through the radially projecting portion of the fitting for swingably supporting the sheath on the upright member, a plurality of telescoped tubes slidably mounted one within the other, the outermost tube being in turn slidably mounted in and extending through the sheath, and counterbalaneing means operatively associated with said sheath.

2. For use with a vehicular body having a floor and front end-wall, a portable derrick comprising a base element adapted to be securely mounted upon the vehicle floor, a pair of spaced parallel upright members carried by the base, a tubular sheath swingably mounted at its upper end between the upper ends of the upright members said tubular sheath being open at both of its ends, and a plurality of telescoped tubes slidably mounted in and extending through the sheath, said sheath being provided at one end with an aperture located in such a manner that when the sheath is swung into substantially upright position between the upright members such aperture will be disposed between the upright members adjacent the base element, a locking bar operably mounted in the lower portion of the upright members for optional engagement with the aperture of the sheath when the sheath is in upright position in which it extends outwardly from the upper end of the sheath, said sheath also being swingable into transport position in which position the lower end of the sheath is swung upwardly away from the base and the telescoped tubes extend through and project outwardly from both ends of the sheath.

3. A portable derrick, as defined in claim 2, and further characterized by spring biased counterbalancing means operatively mounted at its one end upon the sheath adjacent the aperture and at its other end to the upper end of one of said uprights.

4. A portable derrick, as defined in claim 2, and further characterized by a block-like element rigidly mounted on and. projecting laterally outwardly from the sheath adjacent to the apertured end thereof, said block-like element being provided with a pair of spaced parallel bore holes, a pair of parallel rods slidably mounted at their lower ends in and extending upwardly through said bore holes, said rods further being rigidly connected at their upper ends by an end-fitting which is pivotally mounted upon the upper end of one of said uprights, coil springs disposed encirclingly around each of said rods and abutting at their lower ends against the block-like element, and adjustment means on each of said rods for abutting against the upper ends of said springs for varying the compression upon said springs.

5. A portable derrick comprising, in combination, a vehicle body having a floor and an upright structure adjacent the front end thereof, a base element adapted to be securely mounted upon the vehicle floor in rearwardly spaced relation to said upright structure, a pair of spaced parallel column-forming members carried by the base, a tubular sheath swingably mounted at its upper end between the upper ends of the column-forming members, said tubular sheath being open at both of its ends and having an internal bore which is uninterrupted from end to end, a plurality of telescoped tubes mounted in and extending through the sheath for optional disposition in derrick-forming position in which the telescoped tubes extend outwardly from the upper end of the sheath, said sheath also being optionally disposable in transport position, in which position the lower end of the sheath is swung upwardly away from the base and the telescoped tubes extend through and project outwardly from both ends of the sheath, and a socket-like element rigidly mounted upon said upright structure in forwardly spaced relation to the column-forming members and in line with the forwardly presented open end of the sheath when the latter is swung up into transport position so that Nam ate 275,689 Mitchell Apr. 10, 1883 6 Name Date Carr Mar. 16, 1915 Overly et al Jan. 23, 1917 Bock Oct. 31, 1939 Rowe July 21, 1942 Manville June 7, 1949 Pospisil Feb. 13, 1951 Bader Sept. 23, 1952 

